N=int(input())
A=list(map(int, input().split()))
B=list(map(int, input().split()))
A=sorted(A);B=sorted(B)
L=[0]
for i in range(N-1):
  c=abs(A[i]-B[i])
  L.append(L[-1]+c)
  
R=[0]
for i in range(N-1):
  c=abs(A[-1-i]-B[-1-i])
  R.append(R[-1]+c)
R=R[::-1]
c=10**15
for i in range(len(L)):
  c=min(c,L[i]+R[i])
  
ans=[]
for i in range(len(L)):
  if c==L[i]+R[i]:
    ans.append(A[i])

ans=sorted(list(set(ans)))
print(len(ans))
print(*ans)